使用Collection重构状态？

Question

Is there a way to refactor calculateState() method to look a bit cleaner and possibly using Laravel collection?

It calculate the outcome state for dispatched qty, refund qty for not in stock and refund qty for return.

It should decrease $this->dispatchedQty if has been Return ("Code": "Return")

Input Json:

$json = '{
      "HistoryState": [
       {
          "Name": "Dispatched",
          "Num": 3
       },
       {
          "Name": "Refunding",
          "Num": 1,
          "Code": "NotInStock"
       },
       {
          "Name": "Refunding",
          "Num": 1,
          "Code": "Return"
       } 
      ]
 }';

$statusItem = new App\Services\State($json);

Expected Output:

2 Dispatched

1 Refund Not In Stock

1 Returned

class State
{
    protected $state;

    protected $dispatchedQty = 0;
    protected $refundNotInStockQty = 0;
    protected $refundReturnQty = 0;

    public function __construct($json)
    {
        $object = json_decode($json);
        $this->state = $object->HistoryState;
        $this->calculateState();
    }

    protected function calculateState()
    {
        foreach($this->state as $state) {
            if ($state->Name == "Dispatched") {
                $this->dispatchedQty+=  $state->Num;
            }

            if ($state->Name == "Refunding") {
                if ($state->Code == "NotInStock") {
                    $this->refundNotInStockQty += $state->Num;
                } else {
                    $this->refundReturnQty += $state->Num;
                    $this->dispatchedQty -=  $state->Num;
                }
            }
        }

        dd($this->dispatchedQty, $this->refundNotInStockQty, $this->refundReturnQty );
    }
}

Answer 1

First, you can work with Laravel collection which is quite powerful and really useful.

You can convert collection from a json type object.

Let's start step by step. Step 1: Let's work on constructor first.

public function __construct($json)
{
    $object = json_decode($json);
    //Convert it to collection
    $this->state = collect($object->HistoryState);
    $this->calculateState();
}

Step 2: Next Refactor your calculateState method.

protected function calculateState()
{
    $stateGroupByName = $this->state->groupBy(["Name", "Code"]);
    dd(
        $stateGroupByName["Dispatched"]->first()->sum('Num'), //Total DispatchedQty
        $stateGroupByName["Refunding"]["Return"]->sum('Num'), //Total ReturnedQty
        $stateGroupByName["Refunding"]["NotInStock"]->sum('Num'), //Total Not instock
    );
}

That's it. Tweak your code as per your requirement.